#e4.1TextProgress Bar.py
import time
scale = 20
print("------执行开始------")
for i in range(scale+1):
    a, b = '**' * i,'..' * (scale - i)
    c = (i/scale)*100
    print("%{:^3.0f}[{}->{}]" .format (c, a, b))
    time.sleep(0.1)
print("------执行结束------")